Field of the Invention
The present invention relates to a discharge device which discharges a sheet.
Description of the Related Art
In an image forming apparatus in an electrophotographic system, an electrostatic recording system, a magnetic recording system, or the like, an unfixed toner image corresponding to image information is formed and borne on a recording material by an image forming process. The unfixed toner image is thermally fixed onto the recording material by a fixing device as a permanent image, and thereafter the recording material is conveyed to the outside of the apparatus by a discharge device disposed at the outlet part of the fixing device.
In the discharge device, a plurality of discharge rollers is attached to a driving shaft at intervals and the driving shaft is rotated by using a driving source provided in the body of the image forming apparatus. The recording material passes between each of the discharge rollers and a follower roll that is pressed against the corresponding discharge roller, and the material is discharged to the outside of the apparatus.
In some discharge devices, a stiffening roller is provided at a position where the discharge roller is not provided on the driving shaft. The outside diameter of the stiffening roller is greater than that of the discharge roller. In addition, a bend is formed in the recording material due to the difference between the outside diameters of the stiffening roller and the discharge roller. As a result, the recording material has a wave shape when viewed from the downstream side in the conveyance direction. Therefore, loading characteristics of the recording material after being discharged to the outside of the apparatus are enhanced.
Since the outside diameter of the stiffening roller is greater than that of the discharge roller, a difference in circumferential speed occurs between the stiffening roller and the discharge roller when the driving shaft and the stiffening roller are integrally rotated. In order to avoid the difference, the stiffening roller can idle about the driving shaft.
In Japanese Patent Laid-Open No. 2006-151617, attaching (assembling) a stiffening roller to a shaft is not considered.
The present invention has been made to solve the problem described above, and it is desirable to enhance a characteristic of assembling a stiffening rotating member to a shaft.